It took some extra time and is perhaps a bit oversized but we were not planning to take any risks anymore.
We drilled 2 30mm holes in a massive ST 52.3 block so the bolts from the diff fit exactly. In these holes the 2 bushing that support the diff will be mounted. We kept the original principle but improved it a bit with stronger materials.
The differential will be fixed with ARP 2000 studs.
Tomorrow it will be welded and painted.